Forming tool



Jan. 16, 1951 R. SUMNER 2,538,284

FORMING TOOL Filed May 28, 1948 5 Sheets-Sheet 1 mvEmoR RALPH SUMNER AT TOP NEYS Jan. 16, 1951, I R, SUMNER 2,538,284

FORMING TOOL Filed May 28, 1948 3 Sheets-Sheet 2 5| INVENTOR RALPH SUMNER mZmm yfiunim fig]. 7 ATTORNEY Jan. 16, 1951 SUMNER 2,538,284

FORMING TOOL Filed May 28, 1948 I 5 Sheets-Sheet 3 lNl/E/UTOP RALPH SUMNER EW 9W ATTORNE Y5 Patented Jan. 16, 1951 UNITED STATES PATENT OFFICE FORMING TOOL Ralph Sumner, Dayton, Ohio Application May 2a, 1948, Serial No. 29,725 Claims. (01. 29-403) This invention relates to forming tools for use on turning machines such as lathes and screw machines, and others.

The use of forming tools, or turning tools to form-cut work-pieces wherein the forming tool consists of a pair of discs positioned in spaced relationship with a segment of the periphery of the discs removed to provide a radial cutting edge is known in the machine tool art. However, when using the forming tools of the present day art for form-turning finished articles, it is only possible to obtain a very few regrindings of the tool before it must be discarded. The major portion of the periphery of the tool is wasted each time a re-sharpening or regrinding of the tool is required. Usually, four or five or six grindings or re-sharpenings is about all that can be obtained with the usual type of form-turning tool. Waste of this kind involves many thousands of dollars in the average manufacturing plant.

Thus, it is an object of this invention to provide a form-turning tool of the disc type wherein substantially the entire periphery of the disc can be used in machining operations.

It is another object of the invention to provide a form-turning tool in accordance with the prior object wherein the discs of the form-turning tool are set angularly relative to one another by means of a wedge-shaped spacer between the discs so that grinding of relief areas in the tool is eliminated, and thus avoid a large wastage of useful cutting surface of the tool.

Still another object of the invention is to provide a form-turning tool in accordance with the foregoing objects wherein it is provided with means for aligning the angularly disposed discs coaxial with a spindle shaft on which they are mounted with the radial cutting edge normal to the spindle shaft.

Further objects and advantages will become apparent from the drawings and the following description.

In the drawings: v

Figure 1 illustrates a machine on which a formturning tool of this invention is applied.

Figure 2 is a top plan view of the forming tool of this invention.

Figure 3 is a side elevational view of the forming tool of Figure 2.

Figure 4 is an end elevational view of the forming tool of Figure 2 as viewed from the left-hand side thereof.

Figure 5 is a perspective elevational view of a wedge-shaped disc that angularly positions the tool-cutting discs relative to each other.

Figure 6 is a perspective elevational view of one of the tool-cutting discs.

Figure '7 is a vertical cross-sectional view illustrating the mounting of the forming tool of this invention on a spindle shaft.

Figure 8 illustrates the mounting of the tool on the toolholder of a machine.

Figure 9 illustrates a modified arrangement of the wedge-shaped spacing disc.

Figure 10 is a side elevational view of a slightly modified form of the tool discs.

Figure 11 is a cross-sectional view illustrating the manner of grinding of a tool according to the prior art.

Figure 12 is a plan View of a modified arrangement of the forming tool of this invention incorporating the same principles as that disclosed in Figure 3.

Figure 13 is a side elevational view of the forming tool of Figure 2.

Figure 14 is an edge elevational view of the forming tool of Figures 12 and 13 taken in a direction looking at the left hand edge of the tool of Figure 13. I

Figure 15 is a perspectiveelevational view of a spacer disc used in the tool illustrated in Figures 12 to 14. v

Figure 16 is an enlarged cross-sectional view taken at the cutting edge of the forming tool to illustrate tool clearances.

Figure 17 is a line diagram illustrating the manner of calculating the clearances and cutting edges of the forming tool.

In this invention the form-turning tool or forming tool It), shown in Figure 1, is adapted to be used on any conventional turning machine, such as a lathe or a screw machine.

In Figure 1 the form-turning tool I0 is illustrated for use on a four-spindle automatic chucking machine in which only one of the spindles of the machine is illustrated.

The machine consists of a bed I I having a gearhead 12 that drives an index plate 13. The index plate carries a plurality of spindles, one of which is shown at M, which carries a chucking collet l5. Thebar stock Hi from which the work-pieces are made extends from the collet l5. The machine may have other work tools carried thereon such as the drill I! supported in the driving spindle l8.

The form-turning tool In of this invention is I adapted to be carried on a cross-slide l9 which may be operated automatically or manually. The form-turning tool I!) is carried on the cross- 3 slide I!) by means of a spindle bolt 20 extending through the head 2|.

The form-turning tool is more particularly illustrated in Figures 2 to 5, inclusive. The tool l consists of a pair of discs 3| and 32 each of which has an axial opening 33 and 34, respectively, to receive a spindle on which the discs are mounted, such as the spindle bolt heretofore referred to.

A spacer disc 35 is positioned between the tool discs 3| and 32; This spacer 35 is provided with an axial opening 36 which also passes over a spindle on which the tool is mounted. The side faces 3'! and 38 of the spacer 35 are positioned angular to each other relative to a plane extending between the faces normal to theaxis of'the disc, thus arranging the disc in, the form. of a wedge-form having a thin portion 39 and a thick portion 43 on diametrically opposite peripheral, edges thereof.

The inner faces 4| and 42. of. the tool discs 3| and 32 respectively are planar surfaces. that engage the angularly disposed faces 3? and 38-of the wedge-form or wedge-shaped disc 35. Thus, when the spacer 35; is positioned. between. the planar faces 4| and. 42 of the tool discs 3| and 32, the discs are set angular to one another. as shown in the plan view of Figure 2 and the edge View of Figure 4.

The wedge-form 35 is positioned between the tool discs 3| and 32 in such a manner that a. line passing between the median points of the thin edge 35 and the thick edge of the wedge-form 35 will be substantially normal to the radial cutting edges 45 and 46 provided on the tool discs 3i and 32 upon removal of a segmental portion of the discs, as illustratedin Figure 3;

The tool discs 3| and 32' are provided with annular ledges 4i and 48 that extend within the opening 36 of the spacer disc 35 to. coaxially align the tool discs and the spaced disc, and" thus insure a predetermined. positioning of the elements relative to each other.

To align the cutting edges 45 and 46- ofthetool discs 3| and 32 respectively in a common plane that is parallel with the axis through the tool, the tool discs 3| and 32 are each provided with a series of circumferentially positioned holes 49 and 5e, respectively. These hol'es 49 and-50 align coaxially when they are in alignment with the thick pcrtion 49 of the spacer disc 35, as shown in Figure 7. An aligning pin 5| extends through the holes 49 and 53 and through a corresponding coaxially aligned elongated hole 52 provided in the spacer 35. This pin, therefore,.performs; two functions, namely, that of. maintaining the wedgeshaped spacer 35 inits selected position relative to the tool discs 3|v and 32 and maintains: the tocl discs SI and 32 in their: selected position to maintain the cutting edges 45 and 46 thereof in a common plane. If desired, a plurality of. alignng pins could be placed through the: assembly by providing a plurality of holes 52 in the'spaces As shown in Figures 3 and fi there are two rows of circumferentially positioned holes50 and 50a in the disc 32, and 49 and 49a in the disc,3|. In the spacer 35 there is positioned the. elongated hole 52 which coaxially aligns with the respective circumferential positions of the holes 50' and 55a and 49 and 49a of the respective tool discs. It will be noted that the holes 50 and 50a and 49 and 49a are disposed in staggered relationship, while the elongated hole 52 is in aligned radial relationship. The arrangement is thereforesuch that a small degree of rotation of the tool discs 3| and 32 will align the respective holes with one another so that actually alignment can occur between the holes upon rotation of the tool discs by only one-half the diameter of the holes. This has an advantage in that only a small amount of the periphery of the tool need be removed at each regrinding or sharpening thereof before the cutting edges 45 and 46 will be in radial alignment. with the respective holes, and thus necessitate only a small removal of the periphery of the tool at each sharpening.

The assembled tool is adapted to be mounted onaspindle bolt 20 and may be supported between clamp members 55 and 56, each of which has a spherical surface 51 and 58, respectively which engages the conical surfaces 59 and 60 provided in the tool discs 3| and 32, respectively. Thus,.when the draw-bolt BI is drawn upon the threaded portion 62 of the spindle 23, the tool assembly-will be placed coaxial on the spindle 20 with a plane through the median point between the tool discs 3| and 32 normal to the axis of the spindle 25.

The same effect canbe obtained by the clamping members 65 and 66 which have outer parallel faces 61 and Bil-and inner angularly disposed" faces 69 and.'|0 which engage the angularly disposed outer faces of the tool discs 3| and 32. The thin portions. TI and 12 of the clamp members 55 and are. disposed diametrically opposite to the thin portion. 39 of the spacer 35 and are retained in this position upon assembly of the tool by means of the aligning pin 5|.

When using forming tools of the disc type for r rough. and finished forming of work-pieces, it

has been the standard practiceto mount the discs parallel to each other normal to the axis of the spindle on which the discs are mounted. When this is done, all of the faces of the tool discs that are adapted to form cutting edges when a segment of. the discis removed, are parallel to each other. Thus, it has previously been necessary to remove a sufficient portion of the working face of the tools to provide relief for the work-piece as it enters the tool and thereby prevent scoring of the parallelfaces formed on the work-piece.

In Figure 11. there'is illustrated the prior practice of placing the tool discs 88 and BI parallel to each other and normal to the axis of a spindle on which they are mounted. The tool discs are provided with the, usual parallel work faces whereby a plurality of cutting edges 82 and 83 are formed on the cutting discs 8| and 8|),respectively.

To prevent scoring of the side walls of the work-piece 85 as the tool advances toward the center of the bar stock to form the work-piece, the faces of discs are ground away to provide relief areas 86 and 81 on the respective tool' discs. In addition to these normal relief areas at the cutting edge it is necessary to provide other vertical relief areas below the cutting edge to permit passage of the work-piece through the tool'without scoring. These other areas are at least equal to and preferably slightly greater than the radius of the surface being turned on the work-piece.

An inspection of Figure 3 will'show that when a work-piece 90 enters between the tool discs 3| and 32, a substantial portion of the tool discs below the cutting edges 45'and 46 is adjacent the work-piece 90. Thus, in the prior art practices it has been necessary to cut away the portion indicated by the letter A on Figure 3 to provide relief areas in which the formed article could rotate without causing scoring of theside walls of the work-piece, and also burning of the tool. This prior practice involves a large amount of waste-for the reason that the accurate form of the tool discs cannot again be obtained until the portion A of the tool discs, shown in Figure 3, would be cut away at least to the dotted line indicated B in Figure 3. Thus, that portion A of the tool would be lost for any useful purpose. In this invention it will be noted, in Figure 4, that the tool discs are set angular to one another. Thus, that portion of the tool discs'below the cutting edges tapers away from the side walls of the work-piece 90. This automatically gives the necessary relief below the cutting edges 45 and 46 of the tool discs to prevent engagement of the parallel side walls with the portion A of the tool discs. Thus, the only relief necessary is that which is required to relieve the actual cutting edge of the tool disc. Therefore, when the tool discs of this invention are re-ground for re-sharpening, it is only necessary to remove that portion of the tool discs to the dotted line indicated C. The portion of the tool discs between the dotted lines C and BI is, therefore; saved, and a great number of regrindings of the tool can be obtained to utilize substantially the entire periphery of the tool discs. I

In Figure 8 there is illustrated a tool mounting for carrying the tool discs on the machine which consists of a pair of serrated discs 50 and 9|.

In Figures 9 and 10 there is illustrated a slightly modified form of the tool discs andthe wedge spacer between them. In this modification the tool discs, represented by thetool disc 32a, is provided with onlya single row of holes I00 to receive the aligning pins between the tool discs to align the cutting edges 46a. 7

The wedge-shaped spacer 35a is provided wit an arcuate slot IOI through which the aligning pin extends between the tool discs placed against the side faces of the spacer 35a. This arrangement allows movement of the aligning pin radially around the axis of the spacer disc 35a to provide for adjustment of there-ground cutting edges 46a normal to a line extending between the median points of the thin edge 39a and the thick edge 40a. of the spacer 35a. Thus, substantially 100% utilization of the peripheral surface of the tool discs can be obtained. Here also, by providing a plurality of slots IN, a plurality of aligning pins can be used.

In Figures 12 to 16 there is illustrated a slightly modified arrangement of the form-turning tool illustrated in Figures 2 to '7 inclusive. In the forming tool illustrated in Figures 2 to 7 inclusive, the spacer disc 35 has been described as being positioned between the tool discs 3| and 32 in a position such that a linebetween the median points of the thin edge andthick edge of the wedge-shaped spacer 35 is normal to the cutting edge of the tool discs '3I and 32. This places the thin edge of the wedge-shaped spacer disc at the top of the forming tool.

However, in Figures 12 to 16 there is illustrated an arrangement of the tool discs and spacer disc wherein a line between the median points of the thin edge and thick edge of the spacer disc is p'ositioned'parallel to the cutting edge of the tool discs. This arrangement therefore places the thin edge of the wedge-shaped spacing disc in line with the cutting edge of the tool discs.

The form-turning tool of the modified arrangement consists of the tool discs I3I and I32 that are similar in construction to the tool discs 3| and 32 previously described. The tool discs are provided with a cut-away portion I33 to form a cutting ledge or edge I46.

A spacer disc I35 is placed between the tool discs I3I and I32. This spacer disc I35 has opposite angular faces like that of the spacer disc 35 and therefore is in the form of a, wedge form This spacer disc I35 is placed between the tool discs I3I and I32 in a position such that a line between the median points of the thin edge I39 and the thick edge I40 of the spacer disc I 35 is parallel to the cutting edge I46 of the tool discs I3I and I32. With the spacer disc I35 positioned between the tool discs I3I and I32 in this manner, the tool'discs will be positioned angular to one another as illustrated in the top plan view of v the forming tool shown in Figure 12.

-The cutting edge I45 cf the tool disc I 3I and the cutting edge I46 of the tool disc I32 are positioned in a plane extending radially of the axis of the tool discs, as shown in Figures 13 and 14.

With the thin edge of the spacer disc I35 being positioned in alignment with the cutting edges I45 and I46 of the tool discs, the angular position of the tool discs obtained thusly will provide for tool relief clearance below the cutting edges I45 and I46. As shown in Figure 14, the angular positioning of the tool discs is such that the arcuateedges and faces of the tool discs below the cutting edges I45 and I46 recede from a lane normal to the axis ofthe cutting discs, thus provicling the needed tool clearance to allow the work-piece formed by the formingtool to pass between the tool discs I3I and I32 .below the cutting edges I45 and I46 without binding, thus eliminating scoring of the work-piece as it passes below the cutting edges I45 and I46.

In Figure'lfi there is illustrated the tool clearance that-is provided on the side edges of the forming tools to prevent scoring of the sides of the work-piece as the tool moves into the stock, the clearances I50 being provided for this purpose; V

The tool discs I3I and I32 are provided with a series of holes I50 and I50a which provide aligning holes for the tool discs in the same manner as previously described with reference to the tool discs 3! and. 32. In this instance, however, the spacer disc I35 is illustrated as being provided with four radially positioned holes I52, each adapted to' receive an aligning pin in the mannerpreviously described.

In Figure 17 there is illustrated the manner by which the tool discs I3! and I32 are ground with their cutting edges in comparison to previous standard practice.

It has previously been stated that previous standard practice was to place the tool discs I3I and I32 parallel to one another, suitable tool clearance being provided under these circumstances in the manner previously described. Thus, in the previous practice, the cutting edges I60 of the tool disc were held parallel to the axis of the tool discs if a right angle cut was to be made, it being understood that angular cuts from this right angle cut would require angular placement of the cutting edges I60 accordingly. The

usual tool clearance I6I was also provided according to the previous standard practice. In the line diagram of Figure 1'? the work is shown at I62.

It will be appreciated that with the tool discs I3I and I32 being positioned angular to one another as illustrated in Figures 12 to 13 with the thin edge of the spacer disc I35 in alignment with the cutting edges M5 and I46 that the ang-ular displacement will alter the angular arrangement of the cutting edges I69 and'the tool clearance iBl. If the tool would be ground according to previous normal practice, the cutting edges I50 would become angular edges 169a, shown in dotted lines, rather than edges for-cutting a right angle. Thus, the angle of the cutting edges IE3 must be recalculated in the tool discs i3! and 32 to take into consideration the angular displacement of the tool discs relative to a plane normal to the axis of the tool 'discs. Also, the tool clearance angles -16! will :also be recalculated .in like manner.

While this recalculation or refiguring of the position of the cutting edges and tool clearances is required when the arrangement of the tool shown in Figure 12 is used, yet this recalculation is not required when the arrangement of the tool illustrated in Figure 2 is used.

It will be appreciated that in the arrangement shown in Figure 2 that all surfaces and lines in radial alignment with the axis of the tool discs and the cutting edges 45 and 48 will remain :parallel to a linenormal to the axis of the tool discs when the tool discs are positioned angularly to one another in the manner-shown in Figure 2.

"While the device disclosed and described herein constitutes a preferred form of the invention, yet it will *be understood that mechanical alterations can be made without departing from the spirit of the invention, and that all modifications that fall within the scope of the appended claims are intended to be included herein.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A forming tool adapted for use on a turning machine comprising, a pair of tool discs forming planar faces at different levels therebetween with the discs positioned coaxial to each other and having an edge portion thereof cut away forming a radial cutting edge, a spacer disc between said tool discs having opposite face sides angular to one another providing a wedge form between said tool discs, said tool discs being angularly supported relative to one another by said face sides of said wedge form, said wedgeform being positioned relative to said tool discs that .a line between the median points of the thin and thick edges thereof is substantially-normal .to the radial cutting edge formedin the tool .discs, aligning means extending between each of said tool discs and said spacer disc to coaxiallylalign the said spacer disc and the said tool discs, and additional aligning means between said tool discs to maintain the radial cutting edge formed in the tool discs in a plane parallel to the axis through the said discs.

2. A forming tool adapted for useon a turning machine comprising, a pair of tool-discs forming planar faces at different levelstherebetween with the discs positioned coaxial to each other and having an edge portion thereof cut away forming a radial cutting edge, a spacer disc between said tool discs having opposite face .sides angular to one another providing a wedge form between said tool :discs, said tool discs being angularly supported relative to one another by said face sides of said wedge form, said wedge -form being positioned relative to said tool discs that .a line between the median points of the thin and thick edges thereof is substantially normal to the radial cutting edge formed in the tool discs, saidspacer disc having an annular axial opening therein, and an annular ledge on .each of said tool discs disposed within said annular opening in said spacer disc and engaging the same to coaxially align said tool discs and said spacer disc.

3. A forming tool adapted for use on a turning machine comprising, a pair of tool discs having planar faces-at diiferent levels on one side'thereof and having an edge portion thereof cut away forming a radial cutting edge, said discs being positioned with the planar faces thereof facing each other, and a spacer disc between said tool discs having opposite face sides angular to one anotherjprov-iding-a wedge form between said tool discs, said tool discs being angularly-suppor-ted relative to one-another by said face sides of said wedge form, said wedge form being positioned relative .to said 'tool discs that a line between the median points of the thin and thick edges thereof is parallel with theradial cutting edge formed in the tool discs.

4. A forming tool adapted for use on a turning machine comprising, a pair of -tool discs forming planar faces at different levels therebetween with the discs positioned coaxial to each other .and having an edge portionthereof cut away forming a radial cutting edge, a spacer disc between said tool discs having opposite face sides angular to one another providing a Wedge form between said tool discs, said tool .discs being angularly supported relative to one another by said face sides of said wedge form, said wedge form being positioned relative to said tool discs that a line betwen the median points of the thin and thick edges thereof is parallel with the radial cutting edge formed in the tool :discs, and pin means extending between said tool discs and through said wedge form to maintain said tool discs -in exact predetermined position relative to each other and relative to said wedge form to maintain the radial cuttingedges provided thereon in a plane through said line parallel to the axis of said discs.

5. A forming tool adapted for use-on a turning machine comprising, a pair of tool discs each having annular coaxial stepped portions thereon at different levels, each of said stepped portions .oneach'of said discs having a uniform thickness throughout the extent of the stepped portion, said discs being positioned coaxial to each-other and having an edge portion thereof cut away forming a radial cutting edge, and aspacerdisc between said tool discs having opposite face sides angular .to one another-of equal-angle relative to a plane through the spacer normal to the axis thereof providing a wedge "form between said tool discs, said tool discs being .angularly supported relative to one another by said facesidesof said wedge form at equal angles relative to a ,plane through said spacer normal ,to the .axis of the assembled spacerand-tool discs, said wedge form being positioned relative to said tool discs that a line between .the median points of the thinand thick edges thereof is substantially normal to the radial cutting edge formed .inthe tooldiscs.

RALPH SUMNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 301,314 Woerd July 1, 1884 1,632,528 Zeidler June 14, 1927 

